Moving map navigation system

ABSTRACT

A navigation system includes a processor and bit-mapped earth surface map image data in a first data storage device accessed by the processor, the processor displaying an image essentially filling a display area of a display screen and centered on any latitude and longitude supplied to the processor, the image having no discontinuities. The processor may receive latitude and longitude inputs from a user via a user input device, or from a global positioning system (GPS) receiver incorporated in the navigation system. The displayed map image may thus be centered at a desired longitude and latitude or at the longitude and latitude of the navigation system itself. The system may include a second data storage device for storing data from and providing data to the processor. Route information such as flight plan data may then be stored in the second data storage device. Information relating to the type of map system displayed and the scale at which it is displayed, to the currently displayed longitude and latitude, and other significant information is always displayed with the displayed map image. Other information is selectably displayed at a peripheral portion of the display area. Overlays may be selectably displayed over the bit-mapped map image display, with corresponding features appropriately aligned. Such overlays may include approach overlays and instrument flight rules route charts.

FIELD OF THE INVENTION

This invention relates generally to navigation systems, and moreparticularly to a portable navigation system capable of displaying mapinformation stored in a unique format, and capable of storing anddisplaying information relating to particular facilities such asairports in the vicinity of the location of the navigation system or inthe vicinity of any location selected relative to the stored mapinformation, and capable of displaying such information in conjunctionwith, and at least in part simultaneously with, a relevant portion ofthe stored map information.

BACKGROUND OF THE INVENTION

Navigation systems that can generate and display geographic map imagesare now available. Typically a navigation system that displays mapimages includes a computer or processor that has stored within itsassociated memory system, such as in secondary storage, datacorresponding to the map images, or data from which the map images maybe derived. The map image data, if stored as bit maps, may be retrievedand essentially directly displayed. The map image data may also bestored in another form, such as vector graphic data, from which thecomputer system may generate a map image.

One increasingly popular use of such navigation systems is forinstallation in mobile vehicles such as automobiles. Such navigationsystems are then provided with a position sensing device, so that theappropriate map image can be selected based on the position of theautomobile, so that the position of the automobile may be displayed onthe map.

One drawback of common navigation systems is the poor quality of the mapimages they display. In systems that generate map images from data suchas vector graphics data, the detail of the map image is generallysparse. Only objects that are specifically recorded in the data aredisplayed. While highly detailed vector graphics images are achievable,substantial processing power is required to generate detailed imageswith the necessary speed, particularly for real-time display ofposition-dependent map images, requiring expensive and/or specializedprocessors and/or taking processor time away from other functions thatthe navigation system might otherwise perform. On the other hand,systems that store detailed map images as bit maps do not store theimages in a uniform format. Without a uniform format, the bit mappedimages have varying size and distortion factors, making it difficult toaccurately determine and display a given location on the map image. Thevarying size also leaves gaps on the screen as one image is replaced byanother. Bit-mapped images also tend not to scale well, providing poorimage quality at extremes of viewing scale.

Another drawback of common navigation systems is lack of portability.Navigation systems generally are installed in vehicles such asautomobiles. The system cannot be easily removed and placed in anothervehicle or carried to another location, and generally do not provide aself-contained power supply for stand-alone operation.

Another problem faced by navigation systems is that of providing adesired level of detailed information in straightforward, easilycomprehensible format. Overly crowded graphics images that include toomuch information can be confusing to the user of the navigation system.

Another problem faced by navigation systems is that of providing aconvenient and useful method of moving around the map independently oftracking the position of the navigation system. A simple method ofmoving to desired portions of a map is needed.

Another problem faced by navigation systems is cost. A navigation systemwith good performance at reasonable cost is desirable.

A problem faced generally by navigation systems used in aeronautics isthat while such information as flight paths, approach vectors, beaconlocations and the like may easily be represented in vector graphics, thevector graphics engines used for such displays cannot easily representthe high level of detail and wealth of information provided by anaeronautical chart.

An object of the invention, therefore, is to provide a navigation systemdisplaying improved aeronautical and other map images stored in a uniqueformat, and providing useful information to the user in astraightforward, easily comprehensible format, with easy methods ofmoving around within the map images, all at reasonable cost such thatboth a portable navigation system and a vehicle-installed navigationsystem becomes practical. These and other objects of the invention willbecome more apparent from the following detailed description of thepreferred embodiment.

SUMMARY OF THE INVENTION

A navigation system includes a processor and bit-mapped earth surfacemap image data in a first data storage device accessed by the processor,the processor displaying an image essentially filling a display area ofa display screen and centered on any latitude and longitude supplied tothe processor, the image having no discontinuities. The processor mayreceive latitude and longitude inputs from a user via a user inputdevice, or from a global positioning system (GPS) receiver incorporatedin the navigation system. The displayed map image may thus be centeredat a desired longitude and latitude or at the longitude and latitude ofthe navigation system itself. The system may include a second datastorage device for storing data from and providing data to theprocessor. Route information such as flight plan data may then be storedin the second data storage device Information relating to the type ofmap system displayed and the scale at which it is displayed, to thecurrently displayed longitude and latitude, and other very significantinformation is always displayed with the displayed map image. Otherinformation, such as information relating to the nearest airport, theGPS receiver status, navigation information from the GPS receiver, andflight plan information may be selectably displayed at a peripheralportion of the display area.

Overlays may be selectably displayed over the bit-mapped map imagedisplay, such as overlays of information or charts with correspondingfeatures appropriately aligned. Chart overlays may include approachoverlays and instrument flight rules route charts.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram of a generally preferred arrangement of componentsof an embodiment of a system of the present invention.

FIG. 2 is a diagram of the presently preferred contents of an element ofthe diagram of FIG. 1.

FIG. 3 is a diagram of the presently preferred contents of anotherelement of the diagram of FIG. 1.

FIG. 4 is a diagram representing a portion of the presently preferreddisplay and command hierarchy of an embodiment of a system of thepresent invention.

FIG. 5 is a diagram representing another portion of the presentlypreferred command hierarchy of an embodiment of a system of the presentinvention.

FIG. 6 is a diagram representing yet another portion of the presentlypreferred command hierarchy of an embodiment of a system of the presentinvention.

FIG. 7 is a diagram representing still another portion of the presentlypreferred command hierarchy of an embodiment of a system of the presentinvention.

FIG. 8 is a diagram representing a portion of a presently preferreddisplay configuration of an embodiment of a system of the presentinvention.

FIG. 9 is a diagram showing another portion of a presently preferreddisplay configuration of and embodiment of a system of the presentinvention.

FIG. 10 is a diagram of still another portion of the presently preferredcommand hierarchy of an embodiment of a system of the present invention.

FIG. 11 is a diagram showing yet another presently preferred displayconfiguration of an embodiment of a system of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 shows a diagram of a presently preferred structure andarrangement for implementing a system according to the presentinvention. A processor 20 is connected to a data storage device orvarious date storage devices so as to receive data therefrom. Datastored for access by the processor 20 includes bit-mapped map image data28, and preferably includes airport and air routing data 30 and magneticvariation data 32. These and other types of data may be organized in anydesirable configuration for facilitating the operation of a navigationsystem of the present invention as described below. The data storagedevice used to hold the bit-mapped map image data 28 is presentlypreferred to be a CD-ROM. Read/write devices may also be employed,however, and portions of the bit-mapped map image data 28 are preferablytemporarily retained or cached in other data storage devices for fasteraccess as desired.

Processor 20 is also connected to a data storage device so as to be ableto store and retrieve data therefrom. Such a data storage device ispresently preferred to be RAM or magnetic media or a combinationthereof, or other similar memory. Flight plan data 34 is stored in sucha device. Data such as flight plan data 34 is preferably preservedduring loss of power. This may be accomplished by battery backed RAM,routine storage to a magnetic media, or other techniques as desired.

The processor 20 is also connected to a display screen 24 for displayingmap images and information to a user, and to at least one user inputdevice 22 such as a keyboard, keypad, touchscreen, mouse, or the like toallow user input.

Processor 20 is also connected to a global positioning system (GPS)receiver 26 for receiving global positioning information.

The bit-mapped map image data 28 includes bit-mapped map image data ofat least one map system, and preferably includes data of a plurality ofmap systems of mutually differing resolutions, such as map systems data42, 44, and 46 shown in FIG. 2. The bit-mapped map image data isproduced for a given map system by scanning the maps of the map systemaccording to the procedure outlined in U.S. patent application Ser. No.08/767,319 filed on Dec. 16, 1996 which is a continuation of applicationSer. No. 08/432,992 filed May 2, 1995 and incorporated herein byreference. Briefly stated, the scanning and image modificationprocedures disclosed in the above application allow standardization ofbit-mapped image data for an entire map system, such that the processor20 may use the data to display a bit-mapped map image centered at anylatitude and longitude input to the processor, if within the map system,such that the map image essentially fills the display screen andcontains no discontinuities except at the boundaries of the map system,if any. The map systems included in the presently preferred navigationsystem preferably include such systems as NOAA's world aeronauticalcharts, NOAA's sectional aeronautical charts, and the Defense MappingAgency's world maps and the like.

As shown in FIG. 3, the airport and air routing data 30 preferablyincludes airport location data 48, airport runway data 52, airportservices data 50, airport communications data 56, and various types ofoverlay data 54. Overlay data 54 preferably includes approach templates,instrument route charts, and other useful information in graphical orother form.

In operation, the navigation system of FIG. 1 is operable in two mainmodes, a GPS track mode and a view maps mode as illustrated in FIG. 4.In either mode, the processor 20 uses the bit-mapped map image data 28to display a bit-mapped map image from a selected map system, with themap image essentially filling the display screen 24 and centered at alatitude and longitude supplied to the processor. In the GPS track mode,the latitude and longitude are supplied to the processor by the GPSreceiver 26, so that the displayed map image is centered at the positionof the navigation system as sensed by the GPS receiver 26. In the viewmaps mode, the latitude and longitude are supplied to the processor 20by the user directly through the user input device 22 or from other datasuch as the airport and air routing data, as selected by the userthrough the user input device 22.

In either the GPS track mode or the view maps mode, the processorupdates the displayed image each time it receives a new latitude andlongitude. Thus if the navigation system is moving, the latitude andlongitude sensed by the GPS receiver changes periodically, and the mapimage is updated, giving the appearance of a single continuouslyscrolling map image moving across the surface of the display area of thedisplay screen.

The features displayed on the display screen in either GPS track mode orview maps mode may be divided into constant display features which arealways shown on the screen and selective display features which areselectively shown on the screen in response to user inputs through theuser input device.

In either GPS track mode or view maps mode, the preferred constantdisplay features include the map image with a pointer or icon showingthe position of the navigation system. The map image preferably isdisplayed over essentially the entire surface of the display area of thedisplay screen, with the other constant display features occupying therelatively small remaining area. The icon is preferably an airplane, andmay if desired be made to point along the displayed map image in thedirection of the ground track as sensed by the GPS receiver.

Other constant display features include menu headings in a menu bar, amap type and scale or zoom level window, a longitude and latitude windowfor displaying the current longitude and latitude of the pointer, amagnetic variation indicator to indicate when magnetic variationcompensation is in use, and a map orientation indicator to indicatewhether North-up or South-up map image orientation is in use.

Selective display features which are displayed selectively according touser inputs through the user input device include a nearest airportwindow, a GPS receiver status window, a navigation information window,and a flight plan information window, and various types of overlay. Inthe view maps mode, the selective display features do not include theGPS receiver status and the navigation information windows, asillustrated in FIG. 4.

The window-type selective display features (all those except the overlayfeature) are preferably displayed overlaying a peripheral portion of thebit-mapped map image. A currently preferred arrangement is shown forexample in FIG. 11. FIG. 11 represents the display area of a displayscreen. The bit-mapped map image occupies essentially all of the displayarea of the display screen, but with the four window-type selectivedisplay features overlaying the bit-mapped map image at the rightperipheral edge thereof. Each of selective display features isindividually selectively displayable. All may be displayed together asshown in FIG. 11, or any combination, or none, may be displayed, asselected by user inputs through the user input device.

When a route such as a flight plan is entered into the navigation systemand selected, the great circle routes between waypoints along the routemay be displayed on the bit-mapped map images. When in GPS trackingmode, the current position of the navigation system is also shown, anthe great circle route from the current position to the next waypointmay also be displayed. Such a display is shown schematically on thebit-mapped map image area in FIG. 11. A great circle route is showngraphically by a line overlaid on the display between waypoints 60 and64. The actual position of the navigation system is shown by pointer 62,and the great circle route from the actual position to the next waypoint64 is also shown by a line overlaid on the display.

These preferred display arrangements provide particular advantages inthat the most basic and important information is always displayed, butis limited to a small, peripheral area of the display area, allowing arelatively large viewing area for the map image. Other important, butmore detailed, information is displayed in windows that are somewhatlarger, but still peripherally located, and which can be closed, whendesired. This provides ease of viewing and comprehending the datapresented on the viewing surface of the display screen.

The overlay feature is not displayed in a particular location on thedisplay area of the display screen. Instead, the overlay feature usesair routing data or other information to overlay various types of chartsor information on the displayed map image in such a manner that theoverlaid features correspond in size, position, and orientation to thefeatures of the bit-mapped map image. Preferred charts for use with theoverlay feature include approach templates for airports and instrumentflight rules route charts. Such charts may be formatted in the airrouting data as bit-mapped or vector graphics images, as desired. Aspecial feature that improves the viewability of the overlaidinformation is that the bit-mapped map image may be dimmed while theoverlaid information remains bright.

The use of bit-mapped map images for the maps displayed in thenavigation system of the present invention, rather than raster graphicsgenerated map images, allows quick access to the various images and lowprocessing overhead to display and move the images. This enables thepresent system to be implemented with low cost processors, and todisplay moving map images quickly and accurately, with real-time displayof the actual position of even a fast-moving vehicle such as anairplane. In one presently preferred embodiment, the present system isembodied in a laptop computer with a CD-ROM drive for the first storagedevice and a hard drive and RAM for the second storage device. APCMIA-socket GPS receiver is employed, and the entire unit is thenportable and, with batteries, cordless. The keyboard and other inputdevices of the laptop serve as the user input device. Processor powerfreed by the use of bit-mapped images is used instead to perform variousother functions relating to the display of useful information along withthe map images.

The use of bit-mapped map images also allows the inclusion of many moredetails than can practically be included in a vector-mapped graphicsdata base. The wealth of detail on the bit-mapped map images is providedwithout large processing power cost. When these images are combined withchart or other overlays, pilots are provided with more information thanwith other navigational systems.

Preferred command hierarchies for an embodiment of a navigation systemof the present invention are shown in FIGS. 5-7. In FIG. 5, preferredcommands under each of the main menu headings are shown.

Under Options, Exit exits the navigation system (for use when running ona laptop or other general purpose computer), Units allows a selection ofthe units of measure used in the various displays. Magnetic Variationtoggles on and off the magnetic variation compensation. Reset GPS resetsthe GPS receiver. Switch Mode toggles between GPS tracking mode and viewmaps mode.

Under Map, Change CD allows a CD containing bit-mapped map image dataand other data to be changed for another. North/South Up toggles theorientation of the map images displayed. Auto Orientation provides anorientation with South-up if and only if the ground track (the directionof travel relative to the ground) is southward, otherwise a North-uporientation is provided. Map 1, Map 2, and Map 3 change the map systemfrom which the currently displayed bit-mapped map image is sourced tothe map system selected. Overlay calls the overlay commands shown inFIG. 6.

As shown in FIG. 6, Approach Plates or IFR Routes may be selected. Otheruseful types of information may also be included as additionalselections. If Approach Plates is selected, the desired approach plateis preferably selected by first selecting an airport, then a runway atthe selected airport. The runway may be selected by number or otherdesignation by the Runway command, or by the types of navigation aidavailable by the Nav. Aid Types command. The appropriate approach plateis then overlaid on the displayed bit-mapped map image withcorresponding features in proper alignment.

Returning to the command hierarchy of FIG. 5, the Zoom commands allowzooming within a given map system. In and Out zoom one level in and out,respectively. The Level choices zoom directly to the indicated zoomlevel.

The Goto commands allow motion around the map apart from GPS trackingand, when executed, automatically cause a switch to view maps mode.Latitude/Longitude allows entry of the latitude and longitude of theposition to which the pointer will move. Airport allows selection of anairport by an official identifier (preferably by ICAO identifier) thenmoves the pointer to the selected airport. Nearest airport moves thepointer to the nearest airport, while the choices numbered 1-5 move thepointer to the selected one of the five next nearest airports.

The Info command allows selection of an airport as with the Gotocommands, but the destination airport (the destination of a currentlyselected flight plan) is an additional choice. Choice of an airportunder the Info command results in display of the information screen orinformation mode shown in FIG. 9, and in the further command hierarchyshown in FIG. 10. The information screen shown in FIG. 9 includes anairport information window containing information about the selectedairport, a runway information window containing information about aselected runway at the selected airport, and a communicationsinformation/runway sketch window, containing either information about aselected communications channel of the selected airport, or a sketch ofthe runways of the selected airport.

The airport information provided in the airport information window ispreferably thorough and detailed, including such information asownership status (civil, military, civil/military, or private), name,City, State, Country, reference longitude and latitude and elevation,magnetic variation, longest runway length and surface type, above groundheight for the airport traffic pattern, services and supplies availablesuch as oxygen types, fuel types, repair types, IFR capability, etc.,and the airport record date.

The runway information provided in the runway information window ispreferably similarly detailed, including such things as the runwayidentifier, the runway longitude and latitude, the length and width ofthe runway, the true and magnetic bearings of the runway, the surfacetype, the lighting type, and the direction of turns for traffic flow.The runway sketch, when shown, gives a representation of the runwayswith true north up, the runway identifiers displayed near each runway,and the selected runway highlighted.

The communications information, when shown, provides details concerningthe communications frequencies of the selected airport, including thenumber of channels, their call signs, types, and frequencies, and anyservices provided by or on each frequency.

The command hierarchy shown in FIG. 10 is used to control the display ofthe information screen. Exit exits the information screen. Airportallows a different airport to be selected. The selections underCommunications allow the communications frequencies to be displayed(Show) and allow toggling to the Next or to the Previous frequency. Theselections under Runway allow the runway diagram to be displayed (Show)and allow toggling to the Next or to the Previous runway.

Returning to the hierarchy shown in FIG. 5, the selections under Planallow modifications to the current flight plan. Add Waypoint allows awaypoint to be added after the current point. Add Destination allows adestination to be added at the end of the current plan. Remove Waypointremoves the current waypoint. Next Waypoint and Previous Waypoint toggleto the next and previous waypoints respectively. Plan Display togglesopen and closed the flight plan information window shown in FIG. 11.Virtual Flight causes the bit-mapped map image display to track throughthe current flight plan, employing and displaying the great circle routebetween waypoints. Flight Plan brings up a command list like that ofFIG. 7 and a display as shown in FIG. 8.

The preferred flight plan display represented in FIG. 8 is a windowhaving column headings across the top of "leg," "from," "to,""distance," and "heading." Multiple (preferably at least three) legs ofthe flight plan are preferably displayed under these headings. Thelayout of information on the middle leg is shown, with the top andbottom legs omitted for clarity. The leg information includes the ICAOidentifiers of the waypoints, and the distance and heading from the"from" way point to the "to" waypoint. Under the ICAO identifiers isdisplayed the name of the "to" waypoint.

Below the plan leg information is a display of the startpoint of theplan, the destination of the plan, and the total distance of the plan.Below that is a display of the plan number and name, and the totalnumber of waypoints in the plan.

The commands in the list in FIG. 7 allow manipulation of the data storedas flight plans and displayed as shown in FIG. 8. Plan Toggle toggles upor down to other plans. Waypoint Toggle toggles up or down to other legswithin a plan, with the selected leg highlighted. Cancel changes allowscanceling all of current editing performed on a flight plan. Entercauses the changes in the currently edited flight plan to be stored,replacing the previous version. Destination adds a destination to theend of the currently displayed flight plan. Delete deletes a currentlyhighlighted leg of a flight plan. Insert inserts a new leg after thecurrently highlighted leg of the flight plan. Reverse reverses thecurrent flight plan. Clear clears the current flight plan from thesecond memory device. Edit allows editing of the highlighted leg of theflight plan. Name allows giving of or editing of a name for the currentflight plan. View forces the map image display into view maps mode andplaces the pointer at the location of the highlighted waypoint ordestination.

In view of the many possible embodiments in which the present inventionmay be implemented, it should be recognized that the illustratedembodiment above is only a preferred example of the invention and shouldnot be taken as a limitation on the scope of the invention. Rather, theinvention is defined by the following claims. We therefore claim as ourinvention all such embodiments as come within the scope and spirit ofthese claims.

We claim:
 1. A method of providing a moving map for use in a navigationsystem, the method comprising:(a) providing a processor; (b) storingfirst data in a computer storage medium for access by the processor, thefirst data including standardized bit-mapped map image of at least onemap system of at least a portion of the surface of the earth, said firstdata is generated and stored by(i) electronically scanning a printed mapto create a stored bit-mapped map image corresponding to the printedmap; (ii) displaying the stored bit-mapped map image for editing; (iii)cropping with image editing software the displayed bit-mapped map imageinto smaller images that are then deleted, moved, sized, and merged backinto the displayed image to remove an unwanted part of the image and toselect the remainder as a map image corresponding to a desiredgeographic area, the map image having discrete boundaries defined byreference grid lines; (iv) moving the boundaries of the displayed mapimage with said image editing software to shape the geographic area intoa predetermined rectangular shape; (v) sizing the displayed map imagewith said image editing software after the image has been shaped tocontain a predetermined pixel area; (vi) permanently storing, in thecomputer storage medium, the displayed map image as a bit-mapped mapimage of the printed map after the displayed image has been shaped andsized, the displayed map image being stored with an identifier of areference point and size of the geographic area represented by theselected map image; and (vii) repeating (i)-(vi) to create a pluralityof digital map images from the printed map, each image having a uniformformat of the predetermined pixel area and an identifier of a referencepoint and size of a geographic area and a uniform shape that can befitted adjacent to each other to form a seamless map comprised of aplurality of such images; (c) providing a user input device for enablinga user to give input to the processor; (d) connecting a globalpositioning system receiver to the processor for providing globalpositioning system data to the processor; (e) displaying, on a displayscreen having a display area, said map images and information, whereinthe processor displays on the display area of the display screen adisplay map image comprising at least a portion of at least one of saidbit-mapped images, the display map image centered on any given longitudeand latitude supplied to the processor, the display map imageessentially filling the display area of the display screen with nodiscontinuities in the image over the entire said at least one mapsystem except at any edges of said at least one map system, and (f)updating the bit-mapped map image whenever a new longitude and latitudeis supplied to the processor.
 2. The method of claim 1 wherein said newlongitude and latitude are supplied to the processor by a selectable oneof the global positioning system receiver and the user input device. 3.The method of claim 1 wherein the first data includes airport dataincluding at least airport locations, names, and official identifiers.4. The method of claim 3 further comprising storing second data from andproviding second data to the processor, wherein the processor stores, assecond data in response to user inputs, information on a first routeincluding a first starting point, a first destination, and any firstwaypoints.
 5. The method of claim 4 wherein any of (1) the firststarting point, (2) the first destination point, and (3) the any firstway points are supplied to the processor from the airport data inresponse to selection, of an airport as any of (1) the first startingpoint, (2) the first destination point, or (3) the any first waypoints,such selection being made by user inputs through the user input device.6. The method of claim 4 wherein the processor stores, as part of saidsecond data in response to said user inputs, information on a secondroute including at least a second starting point, a second destination,and any second waypoints.
 7. The method of claim 6 wherein the processorselectively displays a current point and a next point of a selectedroute.
 8. The method of claim 6 wherein the processor automaticallyreverses a selected route in response to a user input through the userinput device.
 9. The method of claim 6 wherein the routes constituteflight plans and wherein the processor uses input from the globalpositioning system receiver to track progress of the navigational systemalong a selected flight plan, and wherein the processor displays over aperipheral portion of the display area a flight plan information windowcontaining information on a present leg and a next leg of the selectedflight plan, the flight plan information window being selectivelydisplayable according to user inputs through the user input device. 10.The method of claim 3 wherein said new longitude and latitude aresupplied to the processor from the first computer storage medium andcorrespond to the location of a selected airport selected by user inputsthrough the user input device.
 11. The method of claim 3 wherein theprocessor displays over a peripheral portion of the display area anavigation information window containing at least information, derivedfrom the global positioning system receiver, on ground track, and, whenavailable, on altitude, the navigation information window beingselectively displayable according to user inputs through the user inputdevice.
 12. The method of claim 3 wherein the processor displays over aperipheral portion of the display area a nearest airport windowcontaining at least the name, location, distance, and heading of theairport nearest to the navigation system, the nearest airport windowbeing selectively displayable according to user inputs through the userinput device.
 13. The method of claim 3 wherein the processor displaysover a peripheral portion of the display area a global positioningsystem receiver status window containing both information on the signalstrengths of each global positioning system signal being tracked by theglobal positioning system receiver, and a tracking mode indicatorindicating whether the global positioning system is in a two-dimensionalor a three-dimensional tracking mode, the global positioning systemreceiver status window being selectively displayable according to userinputs through the user input device.
 14. The method of claim 3 whereinthe airport data includes information on runways, communications,navigational facilities, and services and supplies available.
 15. Themethod of claim 1 wherein the first data includes standardizedbit-mapped image data of at least two map systems of differing scale.16. The method of claim 15 wherein one of the at least two map systemscomprises world aeronautical charts.
 17. The method of claim 15 whereinone of the at least two map systems comprises sectional aeronauticalcharts.
 18. The method of claim 15 wherein the first data includesstandardized bit-mapped image data of at least three maps of mutuallydiffering scales.
 19. A navigation system comprising: a processor;acomputer-readable storage medium including both bit-mapped map imagedata of at least one system of earth surface maps, and overlay data,readable by the processor; a user input device for providing user inputto the processor; a display device connected to the processor fordisplaying images and information, the processor producing, from thebit-mapped map image data, and displaying on the display device, inresponse to any longitude and latitude supplied to the processor, abit-mapped map image essentially filling the display area of the displaydevice and having no discontinuities except at any edges of the mapsystem, and centered at the supplied longitude and latitude, theprocessor displaying in response to user inputs an overlay accuratelyoverlaid on and scaled to the bit-mapped map image,wherein thebit-mapped map image data comprises map image data produced by theprocess of (i) electronically scanning a printed map to create a storedbit-mapped map image corresponding to the printed map; (ii) displayingthe stored bit-mapped map image for editing; (iii) cropping with imageediting software the displayed bit-mapped map image into smaller imagesthat are then deleted, moved, sized, and merged back into the displayedimage to remove an unwanted part of the image and to select theremainder as a map image corresponding to a desired geographic area, themap image having discrete boundaries defined by reference grid lines;(iv) moving the boundaries of the displayed map image with said imageediting software to shape the geographic area into a predeterminedrectangular shape; (v) sizing the displayed map image with said imageediting software after the image has been shaped to contain apredetermined pixel area; (vi) permanently storing, in thecomputer-readable storage medium, the displayed map image as saidbit-mapped map image of the printed map after the displayed image hasbeen shaped and sized, the displayed map image being stored with anidentifier of a reference point and size of the geographic arearepresented by the selected map image; and (vii) repeating (i)-(vi) tocreate a plurality of digital map images from the printed map, eachimage having a uniform format of the predetermined pixel area and anidentifier of a reference point and size of a geographic area and auniform shape that can be fitted adjacent to each other to form aseamless map comprised of a plurality of such images.
 20. The navigationsystem of claim 19 wherein the navigation system further comprises aglobal positioning system receiver for providing global positioninginformation to the processor, and wherein the computer-readable storagemedium includes airport identification and location data, and whereinthe any longitude and latitude supplied to the processor is suppliedfrom a selectable one of the user input device, the airport locationdata from the computer-readable storage medium, and the globalpositioning system receiver.
 21. The navigation system of claim 19wherein the bit-mapped map image is selectively dimmed according to auser input from the user input device while a simultaneously displayedoverlay overlaid on and scaled to the bit-mapped map image remainsundimmed.
 22. The navigation system of claim 19 wherein the overlaycomprises an airport approach plate.
 23. The navigation system of claim19 wherein the overlay comprises instrument flight rules route charts.24. The navigation system of claim 19 wherein the bit-mapped map imagedata includes bit-mapped map image data of at least two systems of mapshaving mutually differing scales, the bit-mapped map image produced bythe processor being formed from the bit-mapped map image data of aselectable one of any of the at least two systems of maps havingmutually differing scales, the overlay displayed so as to be accuratelyoverlaid on and scaled to the bit-mapped map image regardless of whichof the at least two systems of maps is selected.